23-|-6|-(+23)
(+15)+(–6);
+15+ (+6);
(–1.1)+(–3.9);
某年级举办足球循环赛,规则是:胜一场得3分,平一场得1分,输一场得-1分,某班比赛结果是胜3场平2场输4场,则该班得 分.